Define "import". Into which application, and by which method?
A CSV file is just text, with no information about column metadata beyond the column names in row one. So this metadata needs to be defined in the target application when a CSV file is read.
If you read CSV files into SAS, you define the variable types and other attributes in the DATA step that reads the file, through a LENGTH, FORMAT and INFORMAT statements (the latter can also be done through the use of informats in the INPUT statement).
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